High security fastener with external shroud retainer

ABSTRACT

An improved fastener comprising a fastener body orientated about a central axis and having a tool-engaging portion, a threaded fastening portion and a shroud-receiving portion; a shroud concentrically mounted in the shroud-receiving portion to rotate relative to the fastener body under an applied external torque and having an outwardly extending annular shoulder; the shroud-receiving portion comprising an inwardly deformed stop radially overlapping the outwardly extending annular shoulder of the shroud; and the deformed stop of the shroud-receiving portion and the annular shoulder of the shroud forming a shroud-retaining element restraining the shroud from movement in at least a first axial direction along the central axis.

TECHNICAL FIELD

The present invention relates to high security fasteners, and moreparticularly to a high security fastener having a shroud or capretainer.

BACKGROUND ART

Locking wheel nuts and wheel bolts are commonly used to attach wheels toaxel hub assemblies of automobiles and other vehicles. These fastenersare designed with security features that are intended to thwart theft byrendering the fasteners difficult to remove with conventional tools. Inparticular, the fasteners do not have the usual hexagonal head patternfound on conventional nuts and bolts and instead have smooth cylindricalsidewalls that cannot be gripped by standard wrenches. Fastener removalrequires the use of a special security tool having a unique key patternthat matches a corresponding groove pattern formed in the fastener endface.

Additional security can be obtained by fitting a free-spinning shroud orcap over the security fasteners cylindrical sidewalls, such that theshroud is in concentric relationship therewith. The shroud discouragesthe use of theft devices that could otherwise be used to grip thesidewalls and remove the fastener without an authorized security tool.Because the shroud substantially surrounds all exposed surfaces of thesidewalls, no rotational purchase can be obtained in the fastener. Thetheft device can only engage the shroud, which freely spins under actionof the theft device while the main body of the fastener remainsstationary.

Various systems have been developed for rotationally retaining theshroud or spin cap on the fastener body. For example, U.S. Pat. No.7,445,414, entitled “High Security Fastener Constructions,” is directedto a shroud fastener design having a shroud retaining system forretaining the shroud for rotation relative to the fastener body. Theentire contents and disclosure of U.S. Pat. No. 7,445,414 areincorporated herein by reference. International Patent Publication No.WO2004/001237, entitled “Screw-Threaded Fastening,” is directed to awheel nut having a fastener body and a spin cap or shroud which isretained on the fastener body by means of an outwardly flared endportion of the fastener body which is received within an undercuttriangular groove in the inner surface of the cap.

BRIEF SUMMARY

With parenthetical reference to corresponding parts, portions orsurfaces of the disclosed embodiment, merely for the purposes ofillustration and not by way of limitation, an improved fastener (15,115, 215, 315) is provided comprising a fastener body (16, 116, 216)orientated about a central axis (x-x); the fastener body having atool-engaging portion (17) to which a driving torque may be applied anda threaded fastening portion (18) configured and arranged to mate with acorresponding threaded element; the fastener body having ashroud-receiving body portion (19, 119, 219) orientated about thecentral axis; a shroud (20, 320) concentrically mounted in theshroud-receiving body portion and having an outer surface (34, 332)facing an inner surface (28, 128) of the shroud-receiving body portion;the shroud being supported in rotatable relationship with theshroud-receiving body portion such that the shroud will rotate relativeto the fastener body under an applied external torque prior to thefastener body rotating when the fastener is engaged with an externalstructure at a design installation torque; the shroud comprising anoutwardly extending annular shoulder (33, 333); the shroud-receivingbody portion comprising an inwardly deformed stop (40, 140, 240, 340)radially overlapping the outwardly extending annular shoulder of theshroud; and the deformed stop of the shroud-receiving body portion andthe annular shoulder of the shroud forming a shroud-retaining elementrestraining the shroud from movement in at least a first axial directionalong the central axis.

The shroud may comprise an annular shroud end surface (35, 331), theshroud-receiving body portion may comprise an annular body end surface(29, 129) facing the shroud end surface, and the annular shroud endsurface and the annular body end surface may be in an opposingorientation and form a second shroud-retaining element restraining theshroud from movement in at least a second axial direction along thecentral axis opposite to the first axial direction along the centralaxis. The shroud-receiving body may comprise an annular end rim portion(41, 141, 241) extending axially beyond the annular shoulder and thedeformed stop (40, 140, 240, 340) of the shroud-retaining element may beformed by a deformation of the rim portion of the shroud-receiving bodyradially inward. The rim may comprise a first cylindrical surface (28)parallel to the central axis and a second frusto-conical surface (26)extending away from the central axis at an acute angle relative to thefirst surface. The deformed stop of the shroud-retaining element maycomprise multiple separate circumferentially arranged and spaced apartdeformed stop elements (240). The deformed stop of the shroud-retainingelement may comprise a continuous deformed annular ring (40, 140, 340).

The inner surface of the shroud-receiving body portion may comprises acylindrical surface (28) having an inside diameter (52); the outersurface of the shroud may comprise a first cylindrical surface (34, 332)having a first outside diameter (51, 351) less than the inside diameterof the inner surface of the shroud-receiving body portion; the shroudmay comprise a second cylindrical surface (32, 334) having a secondoutside diameter (50, 350) less than the first outside diameter; and theshroud may comprise an intermediate outer surface (33, 333) extendingaxially between the first cylindrical surface and the second cylindricalsurface. The intermediate surface may comprise a frusto-conical surfaceor a concaved curved annular surface (33) defining the shoulder. Theintermediate surface may comprise an annular surface orientatedperpendicular to the central axis defining the shoulder. The secondcylindrical surface having a second outside diameter less than saidfirst outside diameter may comprise an inner surface (334) of an annulargroove (357) formed in the first cylindrical surface (332/336) of theouter surface of the shroud and the intermediate surface may comprisesan annular side surface (333) of the annular groove orientatedperpendicular to the central axis and defining the shoulder.

The fastener body comprises a lock nut or a lock bolt. The fastener bodymay be formed of a first material and the shroud may be formed of asecond material substantially softer than the first material. Thefastener body may be formed of a first material and the shroud may beformed of a second material substantially more deformable than the firstmaterial. The fastener body (119) may comprise a cold formed grain flow(60) substantially parallel to the central axis and the deformed stop(140) of the shroud-receiving body portion may comprise aninwardly-curved U-shaped grain flow (61).

In another aspect, a method of forming a fastener is provided comprisingthe steps of providing a fastener body (16, 116) orientated about acentral axis (x-x); the fastener body having a tool engaging portion(17) to which a driving torque may be applied, a threaded fasteningportion (18) configured and arranged to mate with corresponding threadedelement, and a shroud-receiving body portion (19, 119) orientated aboutthe central axis; providing a shroud (20); mounting the shroudconcentrically in the shroud-receiving body portion such that an outersurface (33, 34) of the shroud faces an inner surface (28, 128) of theshroud-receiving body portion; axially aligning an outwardly extendingannular shoulder of the shroud with a deformable rim portion (41, 141)of the shroud receiving body; restraining the fastener body from movingin a first direction along the central axis; applying an axial force tothe deformable rim portion of the shroud receiving body such that thedeformable portion of the shroud receiving body deforms inwardly underthe applied axial force to form an inwardly deformed stop (40, 140)radially overlapping the outwardly extending annular shoulder of theshroud; such that the shroud is restrained from movement in at least oneaxial direction along the central axis.

The shroud may comprise an annular shroud end surface, theshroud-receiving body portion may comprise an annular body end surfacefacing the shroud end surface, and the annular shroud end surface andthe annular body end surface may be in an opposing orientation and forma second shroud-retaining element restraining the shroud from movementin at least a second axial direction along the central axis opposite tothe first axial direction along the central axis. The deformable rimportion of the shroud receiving body may comprise an annular end rimportion extending axially beyond the annular shoulder. The deformablerim portion of the shroud receiving body may comprise a firstcylindrical surface parallel to the central axis and a secondfrusto-conical surface extending away from the central axis at an acuteangle relative to the first surface. The step of applying an axial forceto the deformable rim portion of the shroud receiving body may compriseapplying one or more axial forces to the deformable rim portion of theshroud receiving body at multiple separate circumferentially arrangedand spaced apart locations on the deformable rim portion of the shroudreceiving body. The deformed stop of the shroud-retaining element maycomprise multiple separate circumferentially arranged and spaced apartdeformed stop elements. The deformable rim portion of the shroudreceiving body may comprise an annular ring and the step of applying anaxial force to the deformable rim portion of the shroud receiving bodymay comprise applying the axial force uniformly around the annular rim.The deformed stop of the shroud-retaining element may comprise acontinuous deformed annular ring. The inner surface of theshroud-receiving body portion may comprise a cylindrical surface havingan inside diameter; the outer surface of the shroud may comprise a firstcylindrical surface having a first outside diameter less than the insidediameter of the inner surface of the shroud-receiving body portion; theshroud may comprise a second cylindrical surface having a second outsidediameter less than the first outside diameter; and the shroud maycomprise an intermediate outer surface extending axially between thefirst cylindrical surface and the second cylindrical surface. Theintermediate surface may comprise a frusto-conical surface or a concavedcurved annular surface defining the shoulder. The intermediate surfacemay comprise an annular surface orientated perpendicular to the centralaxis defining the shoulder. The second cylindrical surface having asecond outside diameter less than said first outside diameter maycomprise an inner surface of an annular groove formed in the firstcylindrical surface of the outer surface of the shroud and theintermediate surface may comprises an annular side surface of theannular groove orientated perpendicular to the central axis and definingthe shoulder. The fastener body may comprise a lock nut or a lock bolt.The shroud-receiving body portion may be cold formed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a first embodiment of an improvedsecurity fastener.

FIG. 2 is a perspective view of the security fastener shown in FIG. 1.

FIG. 3 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 1.

FIG. 4 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 1.

FIG. 4A is an enlarged view of the security fastener shown in FIG. 4,taken generally within the indicated oval of FIG. 4.

FIG. 5 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 1.

FIG. 5A is an enlarged view of the security fastener shown in FIG. 5,taken generally within the indicated oval of FIG. 5.

FIG. 6 is a side elevation view of a second embodiment of an improvedsecurity fastener.

FIG. 7 is a perspective view of the security fastener shown in FIG. 6.

FIG. 8 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 6.

FIG. 9 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 6.

FIG. 9A is an enlarged view of the security fastener shown in FIG. 9,taken generally within the indicated oval of FIG. 9, and showing thegrain flow of the fastener body.

FIG. 10 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 6.

FIG. 10A is an enlarged view of the security fastener shown in FIG. 10,taken generally within the indicated oval of FIG. 10, and showing thegrain flow of the fastener body.

FIG. 11 is a side elevation view of a third embodiment of an improvedsecurity fastener.

FIG. 12 is a perspective view of the security fastener shown in FIG. 11.

FIG. 13 is a right side elevation view of the security fastener shown inFIG. 11.

FIG. 14 is a side elevation view of a fourth embodiment of an improvedsecurity fastener.

FIG. 15 is a perspective view of the security fastener shown in FIG. 14.

FIG. 16 is a pre-assembled exploded longitudinal vertical sectional viewof the security fastener shown in FIG. 14.

FIG. 17 is a pre-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 14.

FIG. 17A is an enlarged view of the security fastener shown in FIG. 17,taken generally within the indicated oval of FIG. 17.

FIG. 18 is a fully-assembled longitudinal vertical sectional view of thesecurity fastener shown in FIG. 14.

FIG. 18A is an enlarged view of the security fastener shown in FIG. 18,taken generally within the indicated oval of FIG. 18.

DETAILED DESCRIPTION OF THE EMBODIMENTS

At the outset, it should be clearly understood that like referencenumerals are intended to identify the same structural elements, portionsor surfaces consistently throughout the several drawing figures, as suchelements, portions or surfaces may be further described or explained bythe entire written specification, of which this detailed description isan integral part. Unless otherwise indicated, the drawings are intendedto be read (e.g., crosshatching, arrangement of parts, proportion,degree, etc.) together with the specification, and are to be considereda portion of the entire written description of the embodiments. As usedin the following description, the terms “horizontal”, “vertical”,“left”, “right”, “up” and “down”, as well as adjectival and adverbialderivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”,etc.), simply refer to the orientation of the illustrated structure asthe particular drawing figure faces the reader. Similarly, the terms“inwardly” and “outwardly” generally refer to the orientation of asurface relative to its axis of elongation, or axis of rotation, asappropriate.

Referring now to FIGS. 1-5A, an improved safety fastener is provided, afirst bolt-type embodiment of which is generally indicated at 15. Boltfastener 15 generally includes fastener body 16 and cap or shroud 20,which rotates about axis x-x relative to fastener body 16. Fastener body16 includes tool engaging portion 17, threaded shank 18 andshroud-retaining portion 19 within which shroud 20 is rotationallysupported. Bolt fastener 15 is installed in a wheel hole such thatshroud retaining portion 19 and shroud 20 are arranged to be exposedoutside the entrance of the hole. The fastening end portion 18 of boltfastener 15 includes a shank that is externally threaded over a portionor all of its length. The bolt fastener is mounted on wheels that haveat least one fastener-receiving recess hole with threads correspondingto the threads of shank 18.

Tool engaging portion 17 of fastener body 16 extends radially outwardbetween fastening portion 18 and shroud-retaining portion 19 andcomprises side wall 22 that is substantially cylindrical in shape. Sidewall 22 is formed with a key-receiving pattern that may be implementedas a set of circumferentially arranged lock pattern grooves 23. Lockpattern configurations that use formations of other grooves may also beused. As can be seen, lock pattern grooves 23 are visible on the annularfront face 24 of tool engaging portion 17 that lies between side wall 22and shroud 20. In order to impart lock pattern uniqueness, lock patterngrooves 23 may be patterned or configured in any suitable alternativemanner, such as by employing a selected number of grooves and/or byvarying other features thereof, such as the spacing between groovesand/or the width, length, depth, profile or other configuration orfeature thereof. Such grooves are configured so that a corresponding key(no shown) may be used to engage lock pattern grooves 23. The keyincludes a socket and a drive portion and the entrance to the socket isformed with a key pattern that may be implemented as a set ofcircumferentially arranged key pattern lobes that are configured andarranged to engage the lock pattern grooves 23 when the socket is placedover the right end of shroud 20 of nut fastener 15. Thus, a key having amatching set of key pattern lobes may be used to engage lock patterngrooves 23 to actuate bolt fastener 15 about axis x-x.

The security key is configured to fit within a gap space to engage thelock pattern and rotate bolt fastener 15. Other tools either will notfit within the gap space or will not be able to properly engage androtate bolt fastener 15 when it is installed at its intended designinstallation torque. The size of the gap can be controlled by sizing thediameter of cylindrical sidewall 22 according to the diameter of therecess hole in which nut fastener 15 is employed. Tool engaging portion17 is arranged so that sidewall 22 is within the wheel hole. In thisposition, the bolt fastener's lock pattern is only exposed inside therecessed wheel hole entrance and access to the bolt fastener's lockpattern is limited by the circumferential gap space between the lockpattern's outside diameter and the wheel hole's inside diameter. Theability of shroud 20 to spin relative to fastener body 16 and fasteningportion 18 thereof provides a security feature that protects nutfastener 15 from being used as a purchase point for an unauthorizedtools. Should an attempt be made to rotate bolt fastener 15 by grippingthe exposed end, cap 20 will tend to spin without any rotation beingimparted to fastener body 16 and fastening portion 18 thereof.

As shown in FIG. 3, shroud 20 has a generally cylindrical configurationelongated along axis x-x, and is generally bounded by leftwardly-facingvertical circular surface 37, inwardly-facing horizontal cylindricalsurface 36, leftwardly-facing vertical annular surface 35,outwardly-facing horizontal cylindrical surface 34, rightwardly-facingconcaved curved annular surface 33, outwardly-facing horizontalcylindrical surface 32, and rightwardly-facing vertical circular surface31. The right portion of surface 34, surface 33 and the left portion ofsurface 32 generally form an outwardly extending annular shoulder 39having first diameter 51 at surface 34 and having second diameter 50 atsurface 32 that is less than diameter 51.

Pre-assembled, as shown in FIG. 3, retaining portion 19 of fastener body16 is a specially configured cylindrical member elongated along axis x-xand is generally bounded by outwardly and rightwardly-facingfrustoconical surface 26, rightwardly-facing vertical annular surface27, inwardly-facing horizontal cylindrical surface 28, andrightwardly-facing vertical annular surface 29. As shown, retainingportion 19 thereby defines inner bore 64, having inside diameter 52 atsurface 28, which is approximately the same size as outside diameter 51of surface 34 of shroud 20. In addition, as shown in FIGS. 4 and 4A, theright inner portion of frustoconical surfaces 26, annular surface 27,and the right portion of surface 28 of retaining portion 19 generallydefine annular end rim portion 41.

In the pre-assembled state shown in FIGS. 4 and 4A, shoulder 39 ofshroud 20 has been placed in inner bore 64 of retaining portion 19 ofbody 16 such that leftwardly-facing surface 35 of end shoulder 39 abutsagainst the outer portion of rightwardly-facing annular end face 29 ofbody 16. As shown, in this pre-assembled state, axial depth 54 of innerbore 64 of retaining portion 19 of body 16 is dimensioned to provideaxial gap 53 between rightwardly-facing annular end face 27 of annularend rim portion 41 of retaining portion 19 and the left outside edge ofsurface 33 of end shoulder 39 of shroud 20. When assembled as describedbelow, axial gap 53 will be reduced as annular end rim portion 41 ofretaining portion 19 deforms inward against shroud 20 and reduces theaxial length along axis x-x of annular end rim portion 41 of retainingportion 19.

To complete assembly of fastener 15, with end shoulder 39 of shroud 20placed within bore 64 of retaining portion 19 of body 16 such thatleftwardly-facing annular surface 35 of end shoulder 39 of shroud 20abuts against the outer annular portion of end face 29 of body 16, asshown in FIGS. 4 and 4A, an axial force is then applied with a ram torightwardly-facing surface 27 of annular end rim portion 41 of retainingportion 19 while fastener body 16 is held stationary in a press or thelike. Such force is great enough to deform or bend annular end rimportion 41 of retaining portion 19 and the right portion of surface 28of retaining portion 19 leftward and inward against opposed surfaces 33and 32 of shroud 20 to form end stop 40, as shown in FIGS. 5 and 5A,which depict the fully assembled configuration of fastener 15. Thus,fastener body 16 and shroud 20 are specially formed such that applying adirected axial force to retaining portion 19 with a ram causes annularend rim portion 41 of retaining portion 19 to flare or deform inwardsinto specially formed shoulder 33 of shroud 20.

When assembled, at least deformed portion 40 of annular end rim portion41 of retaining portion 19 radially overlaps shoulder 33 of shroud 20,thereby retaining shroud 20 within the end of body 16 such that shroud20 is free to rotate about center axis x-x of body 16 but is restrainedfrom moving axially to the right out of retaining portion 19 and body16. Thus, as shown in FIGS. 5 and 5A, continuous deformed annular ringstop 40 is formed, which extends inwardly transverse to central axis x-xand has at least a portion that overlaps radially with surface 33 of endshoulder 39 of shroud 20. Opposed surface 29 of retaining portion 19 ofbody 16 and surface 35 of shroud 20, retain shroud 20 such that shroud20 is free to rotate about center axis x-x of body 16 but is restrainedfrom moving axially to the left.

Shroud 20 is thereby mounted concentrically in retaining portion 19 ofbolt fastener 15 such that it does not move axially out of retainingportion 19 but is substantially free to rotate about axis x-x relativeto fastener body 16. Although exterior surfaces 34 and 32 of shroud 20are shown as being substantially cylindrical, and surface 33 is shown asbeing substantially concaved and sloped, other cross-sectional profiles,shapes, or contours could be used to form a retaining shoulder orprotrusion. For example, and without limitation, surface 33 could be arightwardly-facing vertical annular surface or an outwardly andrightwardly-facing frustoconical surface, or other alternative steppedor rightwardly-facing contoured surfaces. Moreover, although shroud 20is shown as being closed-ended on one side, alternatively it may have anopen-ended configuration. If desired, shroud 20 may comprise a cap havea decorative finish to improve fastener appearance, including, but notlimited to, nickel/chrome plating, silver or gray coatings. Furthermore,and without limitation, shroud 20 may be a decorative cap that is madeof a material that is substantially softer or more malleable that thematerial of retaining portion 19. Without limitation, such cap may beplastic, rubber or ceramic or may have a coating that is plastic,rubber, ceramic, anodized or organic. In addition, shroud 20 may bestainless steel, fastener body 16 may not be stainless steel, and anisolation element or layer may be placed between the contacting surfacesof shroud 20 and fastener body 16.

While forming stop 41 by applying a single axial force with a ram toexposed end rim portion 41 of retaining portion 19 while fastener body16 is held stationary in a press has been described, more than a singleaxial ramming force may be applied or such force may be applied at anangle relative to axis x-x.

The described retaining system provides a number of advantages. First, agreater variety of cap or shroud materials and cap or shroud designs maybe used because no force is applied to the cap or shroud to formrestraining element 41. Restraining element 41 is formed from thematerial of fastener body 16, rather than cap or shroud 20, and an axialramming force is applied to fastener body 16, rather than cap or shroud20. Second, the materials of fastener body 16 and shroud 20 may differsignificantly in hardness. For example and without limitation, fastenerbody 16 may have a greater hardness than shroud 20 or fastener body 16may be of a material more elastic than shroud 20. As described furtherbelow, fastener body 16 may be cold formable such that it may not needto be machined. In this manner, the grain flow of a cold formed fastenerbody 16 may be parallel to the longitudinal axis x-x of the fastener.

Referring now to FIGS. 6-10A, a bolt-type security fastener 115according to a second example embodiment is shown. Fastener 115 has mostof the features of fastener 15 described above in connection with FIGS.1-5A. Tool engaging portion 17, threaded shank 18 and shroud 20 offastener 115 are of the same configuration as tool engaging portion 17,threaded shank 18 and shroud 20 of fastener 15. The major differencebetween fastener 15 and fastener 115 lies in the fact that annular endrim portion 141 of retaining portion 119 of fastener 115 is of a squaredconfiguration as compared to tapered annular end rim portion 41 ofretaining portion 19 of fastener 15.

As shown in FIG. 8, retaining portion 119 of fastener body 116 is aspecially configured cylindrical member elongated along axis x-x and isgenerally bounded by rightwardly-facing vertical annular surface 126,inwardly-facing horizontal cylindrical surface 128, andrightwardly-facing vertical annular surface 129. As shown in FIGS. 9 and9A, the inner portion of annular surface 126 and the right portion ofsurface 128 of retaining portion 119 generally define annular end rimportion 141.

In the pre-assembled state shown in FIG. 9, shroud 20 has been placed ininner bore 164 of retaining portion 119 of body 116 such thatleftwardly-facing surface 35 abuts against the outer portion ofrightwardly-facing annular end face 129 of body 116. As shown, in thispre-assembled state, axial depth 154 of inner bore 164 of retainingportion 119 of body 116 is dimensioned to provide axial gap 153 betweenrightwardly-facing annular surface 126 of annular end rim portion 141 ofretaining portion 119 and the left outside edge of surface 33 of shroud20.

To complete assembly of fastener 115, with shoulder 139 of shroud 20placed within bore 164 of retaining portion 119 of body 116 such thatleftwardly-facing annular surface 35 of shoulder 139 of shroud 20 abutsagainst the outer annular portion of end face 129 of body 116, as shownin FIGS. 9 and 9A, an axial force is then applied with a ram to theinner portion of rightwardly-facing surface 126 of annular end rimportion 141 of retaining portion 119 while fastener body 116 is heldstationary in a press or the like. Such force is great enough to deformor bend annular end rim portion 141 of retaining portion 119 and theinner portion of surface 126 of retaining portion 119 inward andleftward against opposed surfaces 33 and 32 of shroud 20 to form endstop 140, as shown in FIGS. 10 and 10A, which depict the fully assembledconfiguration of fastener 115. Thus, fastener body 116 and shroud 20 arespecially formed such that applying a directed axial force to retainingportion 119 with a ram causes annular end rim portion 141 of retainingportion 119 to flare or deform inwards into specially formed shoulder 33of shroud 20.

When assembled, at least deformed portion 140 of annular end rim portion141 of retaining portion 119 radially overlaps shoulder 33 of shroud 20,thereby retaining shroud 20 within the end of body 116 such that shroud20 is free to rotate about center axis x-x of body 116 but is restrainedfrom moving axially to the right out of retaining portion 119 and body116. Thus, as shown in FIG. 10, continuous deformed annular ring stop140 is formed, which extends inwardly transverse to central axis x-x andhas at least a portion that overlaps radially with surface 33 of endshoulder 139 of shroud 20. Opposed surface 129 of retaining portion 119of body 116 and surface 35 of shroud 20, retain shroud 20 such thatshroud 20 is free to rotate about center axis x-x of body 116 but isrestrained from moving axially to the left.

As shown in FIGS. 9A and 10A, in this embodiment fastener body 116 iscold formed with a grain flow parallel to the longitudinal axis x-x offastener 115. Thus, in the preassembled state shown in FIG. 9A, thegrain flow of end rim portion 141 of retaining portion 119 islongitudinal or substantially parallel to axis x-x. When the axial forceis applied with a ram to the inner portion of rightwardly-facing surface126 of annular end rim portion 141 of retaining portion 119 whilefastener body 116 is held stationary in a press or the like, such forceis great enough to deform or bend annular end rim portion 141 ofretaining portion 119 such that grain flow 61 of resulting deformed stop140 is inwardly-curved U-shaped.

Referring now to FIGS. 11-13, a bolt-type security fastener 215according to a third example embodiment is shown. Fastener 215 has mostof the features of fastener 15 described above in connection with FIGS.1-5A. Tool engaging portion 17, threaded shank 18 and shroud 20 offastener 115 are of the same configuration as tool engaging portion 17,threaded shank 18 and shroud 20 of fastener 15. The major differencebetween fastener 15 and fastener 215 lies in the fact that deformed stop240 of shroud-retaining element 219 comprises multiple separatecircumferentially arranged and spaced apart deformed stop elements,severally indicated at 240.

As shown in FIGS. 11-13, retaining portion 219 of fastener body 216 isof the same configuration as retaining portion 19 of fastener body 16 offastener 15. However, to complete assembly of fastener 215, with theshoulder of shroud 20 placed within the bore of retaining portion 219 ofbody 216, rather than applying a uniform annular axial force to annularrim portion 241 of fastener body 216, such axial force is applied ateight circumferentially spaced points about annular rim portion 241 offastener body 216 with a specially configured ram while fastener body216 is held stationary in a press or the like. Such force is greatenough to deform or bend circumferentially spaced portions of annularend rim portion 241 of retaining portion 219 inward and leftward againstopposed surfaces 33 and 32 of shroud 20 to form multiplecircumferentially spaced end stops 240, as shown in FIG. 13, whichdepicts the fully assembled configuration of fastener 215. Thus,applying such pointed circumferentially spaced directed axial forces toretaining portion 219 with a specially configured ram causes onlycircumferentially spaced portions 240 of annular end rim portion 241 ofretaining portion 219 to flare or deform inwards into shoulder 33 ofshroud 20, providing a staked inwardly deformed stop 240 radiallyoverlapping the outwardly extending annular shoulder of the shroud.While eight such staked deformed portions 240 are shown and described inthis embodiment, it is contemplated that more or fewer than eightcircumferentially spaced deformed portions may be employed and that thespacing between such deformed portions about the annular rim may bevaried as desired. For example, and without limitation, three deformedportions spaced equally about the annular rim might be provided.

When assembled, at least deformed portions 240 of annular end rimportion 241 of retaining portion 219 radially overlap shoulder 33 ofshroud 20, thereby retaining shroud 20 within the end of body 216 suchthat shroud 20 is free to rotate about center axis x-x of body 216 butis restrained from moving axially to the right out of retaining portion219 and body 216. Thus, as shown in FIG. 13, a plurality of annularlyspaced deformed stops 240 are formed, each of which extends inwardlytransverse to central axis x-x and has at least a portion that overlapsradially with surface 33 of end shoulder 39 of shroud 20.

Referring now to FIGS. 14-18A, a bolt-type security fastener 315according to a fourth example embodiment is shown. Fastener 315 has mostof the features of fastener 15 described above in connection with FIGS.1-5A. Tool engaging portion 17, threaded shank 18 and shroud-retainingportion 19 of fastener 315 are of the same configuration as toolengaging portion 17, threaded shank 18 and shroud-retaining portion 19of fastener 15. The major difference between fastener 15 and fastener315 lies in the fact that shoulder 333 of shroud 320 is formed by agroove in the outwardly-facing cylindrical surface of shroud 320.

As shown in FIG. 18A, shroud 320 has a generally cylindricalconfiguration elongated along axis x-x, and is generally bounded byleftwardly-facing vertical circular surface 337, inwardly-facinghorizontal cylindrical surface 330, leftwardly-facing vertical annularsurface 331, outwardly-facing horizontal cylindrical surface 332,rightwardly-facing vertical annular surface 333, outwardly-facinghorizontal cylindrical surface 334, leftwardly-facing vertical annularsurface 335, outwardly-facing horizontal cylindrical surface 336, andrightwardly-facing vertical circular surface 338. The right portion ofsurface 332, surface 333 and surface 334 form an outwardly extendingannular shoulder 339 having first diameter 351 at surface 332 and havingsecond diameter 350 at surface 334, which is the base of groove 357defined by surfaces 333, 334 and 335, that is less than diameter 351.

In the pre-assembled state shown in FIG. 17, shroud 20 has been placedin inner bore 64 of retaining portion 19 of body 16 such thatleftwardly-facing surface 331 abuts against the outer portion ofrightwardly-facing annular end face 29 of body 16. As shown, in thispre-assembled state, axial depth 54 of inner bore 64 of retainingportion 19 of body 16 is dimensioned to provide axial gap 353 betweenrightwardly-facing annular surface 27 of annular end rim portion 41 ofretaining portion 19 and surface 333 of groove 357 of shroud 20.

To complete assembly of fastener 315, with shoulder 339 of groove 357 ofshroud 320 placed within bore 64 of retaining portion 19 of body 16 suchthat leftwardly-facing annular surface 331 of shroud 320 abuts againstthe outer annular portion of end face 29 of body 16, as shown in FIGS.17 and 17A, an axial force is then applied with a ram torightwardly-facing surface 27 of annular end rim portion 41 of retainingportion 19 while fastener body 16 is held stationary in a press or thelike. Such force is great enough to deform end rim portion 41 ofretaining portion 19 and inner surface 28 of retaining portion 19 inwardagainst opposed surfaces 333 and 334 of groove 357 of shroud 320 to formend stop 340, as shown in FIGS. 18 and 18A, which depict the fullyassembled configuration of fastener 315. Thus, fastener body 16 andshroud 320 are specially formed such that applying a directed axialforce to retaining portion 19 with a ram causes annular end rim portion41 of retaining portion 19 to flare or deform inwards into groove 357and shoulder 333 of shroud 320.

When assembled, at least deformed portion 340 of annular end rim portion41 of retaining portion 19 radially overlaps shoulder 333 of shroud 320,thereby retaining shroud 320 within the end of body 16 such that shroud320 is free to rotate about center axis x-x of body 16 but is restrainedfrom moving axially to the right out of retaining portion 19 and body16. In this embodiment, due to the structure of groove 357 andleftwardly-facing annular surface 335 opposite surface 333, deformedportion 340 also restrains shroud 320 from moving axially to the left.Thus, as shown in FIG. 18, continuous deformed annular ring stop 340 isformed in groove 357, which extends inwardly transverse to central axisx-x and has at least a portion that overlaps radially with surface 333of end shoulder 339 of shroud 320.

The present disclosure contemplates that many changes and modificationsmay be made. Therefore, while forms of the improved fastener have beenshown and described, and a number of alternatives discussed, personsskilled in this art will readily appreciate that various additionalchanges and modifications may be made without departing from the scopeof the invention, as defined and differentiated by the following claims.

What is claimed is:
 1. A method of forming a fastener comprising thesteps of: providing a fastener body orientated about a central axis;said fastener body having a tool engaging portion to which a drivingtorque may be applied, a threaded fastening portion configured andarranged to mate with corresponding threaded element, and ashroud-receiving body portion orientated about said central axis;providing a shroud; mounting said shroud concentrically in saidshroud-receiving body portion such that an outer surface of said shroudfaces an inner surface of said shroud-receiving body portion; axiallyaligning an outwardly extending annular shoulder of said shroud with adeformable rim portion of said shroud receiving body portion;restraining said fastener body from moving in a first direction alongsaid central axis; applying an axial force to said deformable rimportion of said shroud receiving body portion such that said deformablerim portion of said shroud receiving body portion deforms inwardly undersaid applied axial force to form an inwardly deformed stop radiallyoverlapping said outwardly extending annular shoulder of said shroud;and such that said shroud is restrained from movement in at least oneaxial direction along said central axis; and such that said shroud ispermitted to rotate about said central axis relative to said fastenerbody under an applied external torque prior to said fastener bodyrotating when said fastener body is engaged with an external structureat a design installation torque.
 2. The method set forth in claim 1,wherein said shroud comprises an annular shroud end surface, saidshroud-receiving body portion comprises an annular body end surfacefacing said shroud end surface, and said annular shroud end surface andsaid annular body end surface are in an opposing orientation and form asecond shroud-retaining element restraining said shroud from movement inat least a second axial direction along said central axis opposite tosaid first axial direction along said central axis.
 3. The method setforth in claim 1, wherein said deformable rim portion of said shroudreceiving body portion comprises an annular end rim portion extendingaxially beyond said annular shoulder.
 4. The method set forth in claim1, wherein said deformable rim portion of said shroud receiving bodyportion comprises a first cylindrical surface parallel to said centralaxis and a second frusto-conical surface extending away from saidcentral axis at an acute angle relative to said first surface.
 5. Themethod set forth in claim 1, wherein said step of applying an axialforce to said deformable rim portion of said shroud receiving bodyportion comprises applying one or more axial forces to said deformablerim portion of said shroud receiving body portion at multiple separatecircumferentially arranged and spaced apart locations on said deformablerim portion of said shroud receiving body portion.
 6. The method setforth in claim 5, wherein said deformed stop of said shroud-retainingelement comprises multiple separate circumferentially arranged andspaced apart deformed stop elements.
 7. The method set forth in claim 1,wherein said deformable rim portion of said shroud receiving bodyportion comprises an annular ring and said step of applying an axialforce to said deformable rim portion of said shroud receiving bodyportion comprises applying said axial force uniformly around saidannular rim.
 8. The method set forth in claim 7, wherein said deformedstop of said shroud-retaining element comprises a continuous deformedannular ring.
 9. The method set forth in claim 1, wherein: said innersurface of said shroud-receiving body portion comprises a cylindricalsurface having an inside diameter; said outer surface of said shroudcomprises a first cylindrical surface having a first outside diameterless than said inside diameter of said inner surface of saidshroud-receiving body portion; said shroud comprises a secondcylindrical surface having a second outside diameter less than saidfirst outside diameter; and said shroud comprises an intermediate outersurface extending axially between said first cylindrical surface andsaid second cylindrical surface.
 10. The method set forth in claim 9,wherein said intermediate surface comprises a frusto-conical surface ora concaved curved annular surface defining said shoulder.
 11. The methodset forth in claim 9, wherein said intermediate surface comprises anannular surface orientated perpendicular to said central axis definingsaid shoulder.
 12. The method set forth in claim 9, wherein said secondcylindrical surface having a second outside diameter less than saidfirst outside diameter comprises an inner surface of an annular grooveformed in said first cylindrical surface of said outer surface of saidshroud and said intermediate surface comprises an annular side surfaceof said annular groove orientated perpendicular to said central axis anddefining said shoulder.
 13. The method set forth in claim 1, whereinsaid fastener body comprises a lock nut or a lock bolt.
 14. The methodset forth in claim 1, wherein said shroud-receiving body portion is coldformed.
 15. The method set forth in claim 1, wherein: said outwardlyextending annular shoulder of said shroud comprises an outer overlapsurface; said inwardly deformed stop of said shroud-receiving bodyportion comprises an inner overlap surface; said inner overlap surfaceof said inwardly deformed stop of said shroud-receiving body portionradially overlaps said outer overlap surface of said outwardly extendingannular shoulder of said shroud; and said inner overlap surface of saidinwardly deformed stop of said shroud-receiving body portion and saidouter overlap surface of said outwardly extending annular shoulder ofsaid shroud are in rotational contact such that said shroud will rotateabout said central axis relative to said fastener body under an appliedexternal torque prior to said fastener body rotating when said fastenerbody is engaged with an external structure at a design installationtorque.
 16. The method set forth in claim 15, wherein: said outwardlyextending annular shoulder of said shroud comprises an innercontact-free surface orientated about said central axis; saidshroud-receiving body portion comprises an inner bore orientated aboutsaid central axis and having an axial depth; and said shroud isrotationally supported in said inner bore of said shroud-receiving bodyportion such that said inner contact-free surface of said outwardlyextending annular shoulder of said shroud is free to rotate in saidinner bore of said shroud-receiving body portion.
 17. The method setforth in claim 16, wherein said inner contact-free surface of saidoutwardly extending annular shoulder of said shroud comprises acylindrical surface having an inside diameter.